In this paper, a novel risk-based, two-objective (technical and economical) optimal reactive power dispatch method in a wind-integrated power system is proposed which is more consistent with operational criteria.  The technical objective includes the minimization of the new voltage instability risk index. The economical objective includes cost minimization of reactive power generation and active power loss. The proposed voltage instability risk employs a hybrid possibilistic (Delphi-Fuzzy)-probabilistic approach that takes into consideration the operator’s experience, the wind speed and demand forecast uncertainties when quantifying the risk index. The decision variables are the reactive power resources of the system. To solve the problem, the modified multi-objective particle swarm optimization algorithm with sine and cosine acceleration coefficients is utilized. The method is implemented on the modified IEEE 30-bus system. The proposed method is compared with those in the previously published literature, and the results confirm that the proposed risk index is better at estimating the voltage instability risk of the system, especially in cases with severe impact and low probability. In addition, according to the simulation results compared to typical security-based planning, the proposed risk-based planning may increase the security and economy of the system due to better utilization of system resources.

Background: Phototherapy is an important modality in dermatology and the number of skin diseases which can be controlled with it IS mcreasmg. In order to start treatment, the first dose of phototherapy is determined by measurement of minimal erythema dose (MED) in each patient individually or according to patient"s skin type. Objective: To determine the relationship of skin type with MED in patients under UV phototherapy referred to Razi Hospital in Tehran Patients and Methods: In patients referred to Razi Hospital in 1381(2002-2003) for UVB phototherapy, skin type was determined according to Fitzpatrick"s classification and MED was measured using a UV-meter. Age, sex and the disease of the patients were also recorded. The data were analysed using one way ANOVA and Welch tests. Results: Eighty patients including 39 males and 41 females were studied. The mean age of the patients was 32 years (SD=15.8). Their diseases include psonasls, vitiligo, parapsoriasis, pityriasis lichenoides chronica, perforating disorder and patch stage mycosis fungoides. The mean of MED in 17patients with skin type Il was 111.8±39.2, in 42 patients with skin type III was 105.9±43.1 and in 21 patients with skin type IV was l14.3±39.2 mJ/cm2 , with no significant statistical difference. Conclusion: The first dose of phototherapy could not be determined based on skin type and measurement of MED is necessary in each patient.

The Markov random field (MRF) theory has been accepted as a highly effective framework for designing noise-tolerant nanometer digital VLSI circuits. In MRF-based design, proper feedback lines are used to control noise and keep the circuits in their valid states. However, this methodology has encountered two major problems that have limited the application of highly noise immune MRF-based circuits. First, excessive hardware overhead that imposes a great cost, power consumption and propagation delay on the circuits and second, separate implementation of feedback lines that adds further delay to the circuits. In this paper, we propose a novel approach for minimal-cost inherent-feedback implementation of low-power MRF-based logic gates. The simulation results, which are based on 32nm BSIM4 models, demonstrate that besides excellent noise immunity of the proposed method, it has the least propagation delay in comparison with all of the previously reported MRF-based gates due to its inherent feedbacks. In addition, the proposed method outperforms competing ones, which have comparable noise immunity, in other circuit metrics like cost and power consumption. Specifically, the proposed method achieves at least 18%, 29%, and 39% reductions in cost, delay and power consumption with considerable noise immunity improvement compared with competing methods.

We define minimal CN-dominating graph MCN (G), commonality minimal CN-dominating graph CMCN (G) and vertex minimal CN-dominating graph M vCN (G), characterizations are given for graph G for which the newly defined graphs are connected. Further serval new results are developed relating to these graphs.

In this paper, a new method for extending and relaxing the noise-coupling (NC) technique is proposed to enhance the noise-shaping order without adding the number of integrators. The noise-shaping order of the introduced ∑∆ modulator whit applying a second-order noise-coupling technique is enhanced and its performance with optimizing the noise transfer function (NTF) zeros is improved. Also, by removing the analog adder at feedforward path and transferring it to a new feedback branch before the last integrator and adding second-order NC path can be decreased the input voltage swing to the quantizer. Thus, by improving the modulator resolution, power consumption can be reduced. Mathematical analyses and behavioural simulation results confirm the effectiveness of the new NC method. To examine its performance, a 2nd-order single loop ΣΔ modulator was designed. The new noise-coupling method is used to achieve the three-order noise shaping to increase the resolution with low complexity and low-power. The results show an outstanding improvement in signal-to-noise and distortion ratio (SNDR) compared to the conventional structure.

‎‎Synchronized systems‎, ‎has attracted much attention in 1986 by F. Blanchard and G. Hansel, and extension of them has been of interest since that notion was introduced in 1992 by D. Fiebig and U. Fiebig. ‎One was via half synchronized systems; that is‎, ‎systems having half synchronizing blocks‎. ‎In fact‎, ‎if for a left transitive ray such as $\ldots x_{-1}x_{0}m$ and $mv$ any block in $X$ one has again $\ldots x_{-1}x_{0}mv$ a left ray in $X$‎, ‎then $m$ is called half synchronizing. ‎A block $m$ is minimal (half-)synchronizing, ‎whenever $w \varsubsetneq m$‎, ‎$w$ is not (half-)synchronizing‎. ‎Examples with $\ell$ minimal (half-)synchronizing blocks has been given for $0\leq \ell\leq \infty$‎.‎‎ ‎‎‎To do this we consider a $\beta$-shift and will replace 1 with some blocks $u_i$‎ ‎to have countable many new systems‎. ‎Then‎, ‎we will merge them‎.‎

Purpose: To assess the efficacy of minimal surgery scleral buckling in patients who were referred to Labbafinejad medical center in a 5 year period.Material and methods: Records of all patients with retinal detachment who had undergone minimal surgery between 1995 and 2000 and were followed up for at least 6 months were retrospectively reviewed. The records were evaluated with respect to clinical features and disease characteristics and the success rate was determined according to anatomic reattachment and visual acuity of better than 20/200. All intraoperative and postoperative complications were reported. Roles of factors such as extent and duration of retinal detachment, macular status, proliferative vitreoretinopathy, evidence of long standing retinal detachment, type of break, myopia, lens status, intra-operative complications, and cryotheraply on success rate were determined. Regression analysis was used to identify the factors which played the main role in success.Results: Seventy patients (72% male, 25% female) underwent minimal surgery scleral buckling. Mean age (SD) was 44 (17.6) years. Oveall operations were successful (92.9%) and 58 patients have good or useful visual outcome (89.2%). Macular detachment significantly increased the failure rate (P<0.04). Regression analysis showed that the extent of retinal detachment had significant correlation with success rate.Conclusion: The success rate of minimal surgery and final visual acuity in this series were acceptable and similar to other experiences. A controlled clinical trial with a longer period of follow up is recomended to determine role of factors such as duration of retinal detachment and pre-operative visual acuity on anatomic and functional results.